This invention relates to a safeguard cap structure, particularly for application to bottles.
There are known several types of safeguard caps, i.e. caps which while permitting a normal issue of the liquid contents out of the bottle, do not let in foreign liquids. Among such known caps are those provided internally with a valve which is movable by gravity, thus allowing the liquid to be poured out of the bottle when the latter is turned more or less upside down but preventing the admixture of foreign liquids when the bottle is in an upright position. Such caps, although generally satisfactory, are prone to sticking of the moving valve member owing to the formation of a crystalline colloidal deposit over the contact areas of the moving valve with its respective stationary seat. Another drawback of the prior art cap configurations is that they are made up of a comparatively high number of component parts, which brings about increased manufacturing and assembling costs.
Italian Patent No. 770,574, issued on June 1, 1960, to one of the applicants discloses a safeguard cap comprising a hollow body which can be associated in sealing engagement with the neck of a bottle, and is provided in the proximity of the upper free edge of said hollow body with a number of upward extending flexible uprights which support a shut off disc. In an open condition, between said free edge and said shut off disc there remain defined outlet ports for the issuing of the liquid from a bottle. When the covering hood is installed, this acts upon the shut off disc causing said flexible uprights to collapse, and the shut off disc to abut on said free edge, thereby a tight seal is achieved. When the cap is screwed out, the uprights extend resiliently upwards, thus uncovering the liquid outlet ports. The embodiment just described, although providing positive results both from a practical point of view and costwise, since it is made up, as it can be observed, of a very limited number of parts, presents a disadvantage in that, when the cap is left in a closed condition over extended periods of time, the elastic strain on the flexible uprights tends to convert into a plastic one, thus preventing the spontaneous lifting of the shut off disc after removal of the hood.